"""Property-based tests: random order streams never violate book, reservation or conservation invariants,
and the event log replays to the same final state."""
import numpy as np
from hypothesis import given, settings, strategies as st

from market_agents.exchange.accounts import Account
from market_agents.exchange.engine import AssetSpec, Exchange, ExchangeConfig
from market_agents.exchange.orders import Action, CancelIntent, OrderIntent, OrderType, Side


def build(seed, n_agents=6, allow_short=False):
    ex = Exchange([AssetSpec(asset=0, name="A0", price_band_pct=0.9)], ExchangeConfig(taker_fee_bps=3.0, maker_fee_bps=-1.0,
                  allow_short=allow_short, max_short_lots=50, order_ttl=7), np.random.default_rng(seed), {0: 1000})
    for i in range(n_agents):
        ex.register(Account(agent_id=i, cash=200_000 * (i + 1), positions={0: 50 * (i + 1)}, short_allowed=allow_short),
                    latency=0.05 + 0.3 * (i % 3))
    return ex


intent = st.tuples(st.integers(0, 5), st.sampled_from([Side.BUY, Side.SELL]), st.sampled_from([OrderType.LIMIT, OrderType.MARKET]),
                   st.integers(1, 80), st.integers(500, 1500), st.booleans())


@settings(max_examples=60, deadline=None)
@given(st.lists(intent, min_size=1, max_size=120), st.integers(0, 10_000))
def test_random_streams_keep_invariants(stream, seed):
    ex = build(seed)
    t = 0
    for k, (agent, side, otype, qty, price, cancel) in enumerate(stream):
        if cancel and ex.orders:
            oid = max(ex.orders)
            ex.submit(ex.orders[oid].agent_id, Action(cancels=[CancelIntent(oid)]), float(t))
        ex.submit(agent, Action(orders=[OrderIntent(0, side, otype, qty, None if otype is OrderType.MARKET else price)]), float(t))
        if k % 3 == 2:
            ex.process_until(float(t + 1))
            ex.end_of_tick(t)
            t += 1
            ex.books[0].check_invariants()
            ex.ledger.check_conservation()
    ex.process_until(float(t + 5))
    ex.books[0].check_invariants()
    ex.ledger.check_conservation()
    # reservations equal the sum over resting orders
    for acc in ex.ledger.accounts.values():
        resting = ex.books[0].resting_for(acc.agent_id)
        assert acc.reserved_cash == sum(o.reserved_cash for o in resting)
        assert acc.reserved_qty.get(0, 0) == sum(o.reserved_qty for o in resting)
        assert acc.positions[0] >= 0


@settings(max_examples=25, deadline=None)
@given(st.lists(intent, min_size=5, max_size=80), st.integers(0, 1000))
def test_determinism_and_replay(stream, seed):
    def run():
        ex = build(seed)
        for k, (agent, side, otype, qty, price, cancel) in enumerate(stream):
            ex.submit(agent, Action(orders=[OrderIntent(0, side, otype, qty, None if otype is OrderType.MARKET else price)]), float(k // 4))
            if k % 4 == 3:
                ex.process_until(float(k // 4 + 1))
        ex.process_until(1e9)
        return ex
    a, b = run(), run()
    assert a.snapshot() == b.snapshot()
    assert [(e.kind, e.payload) for e in a.events] == [(e.kind, e.payload) for e in b.events]